Foo Fighters frontman Dave Grohl initially recorded seven instrumentals with no intention of releasing them or even singing on the tracks. But he slowly farmed out his basic tracks to several metal heroes, who added vocals to the ragged riffs to form Probot, who are set to release their self-titled debut album on Tuesday (February 10). “I came up with my wish list of all of my favorite singers from this era,” Grohl tells RollingStone.com, “which is ’82 to ’89 underground metal, and all the bands I listened to at the time: Eric Wagner from Trouble and Snake from Voivod and Cronos [from Venom] and Lemmy and Wino. We started making phone calls trying to find all these people.” Grohl played virtually all the instruments himself, though Lemmy and Cronos play bass on their tracks, Wino adds explosive guitar to ‘The Emeerald Law’, and Kim Thayil of Soundgarden plays guitar on two songs.